XZ Utils  5.2.10
Data Structures | Macros | Functions
file_io.h File Reference

I/O types and functions. More...

Data Structures

union  io_buf
 
struct  file_pair
 

Macros

#define IO_BUFFER_SIZE   8192
 

Functions

void io_init (void)
 Initialize the I/O module. More...
 
void io_write_to_user_abort_pipe (void)
 Write a byte to user_abort_pipe[1]. More...
 
void io_no_sparse (void)
 Disable creation of sparse files when decompressing. More...
 
file_pairio_open_src (const char *src_name)
 Open the source file. More...
 
bool io_open_dest (file_pair *pair)
 Open the destination file. More...
 
void io_close (file_pair *pair, bool success)
 Closes the file descriptors and frees possible allocated memory. More...
 
size_t io_read (file_pair *pair, io_buf *buf, size_t size)
 Reads from the source file to a buffer. More...
 
void io_fix_src_pos (file_pair *pair, size_t rewind_size)
 Fix the position in src_fd. More...
 
bool io_pread (file_pair *pair, io_buf *buf, size_t size, off_t pos)
 Read from source file from given offset to a buffer. More...
 
bool io_write (file_pair *pair, const io_buf *buf, size_t size)
 Writes a buffer to the destination file. More...
 

Detailed Description

I/O types and functions.

Function Documentation

◆ io_init()

void io_init ( void  )

Initialize the I/O module.

◆ io_write_to_user_abort_pipe()

void io_write_to_user_abort_pipe ( void  )

Write a byte to user_abort_pipe[1].

This is called from a signal handler.

◆ io_no_sparse()

void io_no_sparse ( void  )

Disable creation of sparse files when decompressing.

References try_sparse.

◆ io_open_src()

file_pair* io_open_src ( const char *  src_name)

◆ io_open_dest()

bool io_open_dest ( file_pair pair)

Open the destination file.

References signals_block().

◆ io_close()

void io_close ( file_pair pair,
bool  success 
)

Closes the file descriptors and frees possible allocated memory.

The success argument determines if source or destination file gets unlinked:

  • false: The destination file is unlinked.
  • true: The source file is unlinked unless writing to stdout or –keep was used.

References file_pair::dest_fd, file_pair::dest_pending_sparse, file_pair::dest_try_sparse, and message_error().

◆ io_read()

size_t io_read ( file_pair pair,
io_buf buf,
size_t  size 
)

Reads from the source file to a buffer.

Parameters
pairFile pair having the source file open for reading
bufDestination buffer to hold the read data
sizeSize of the buffer; assumed be smaller than SSIZE_MAX
Returns
On success, number of bytes read is returned. On end of file zero is returned and pair->src_eof set to true. On error, SIZE_MAX is returned and error message printed.

Referenced by coder_passthru().

◆ io_fix_src_pos()

void io_fix_src_pos ( file_pair pair,
size_t  rewind_size 
)

Fix the position in src_fd.

This is used when –single-thream has been specified and decompression is successful. If the input file descriptor supports seeking, this function fixes the input position to point to the next byte after the decompressed stream.

Parameters
pairFile pair having the source file open for reading
rewind_sizeHow many bytes of extra have been read i.e. how much to seek backwards.

◆ io_pread()

bool io_pread ( file_pair pair,
io_buf buf,
size_t  size,
off_t  pos 
)

Read from source file from given offset to a buffer.

This is remotely similar to standard pread(). This uses lseek() though, so the read offset is changed on each call.

Parameters
pairSeekable source file
bufDestination buffer
sizeAmount of data to read
posOffset relative to the beginning of the file, from which the data should be read.
Returns
On success, false is returned. On error, error message is printed and true is returned.

References message_error(), and file_pair::src_fd.

Referenced by parse_check_value().

◆ io_write()

bool io_write ( file_pair pair,
const io_buf buf,
size_t  size 
)

Writes a buffer to the destination file.

Parameters
pairFile pair having the destination file open for writing
bufBuffer containing the data to be written
sizeSize of the buffer; assumed be smaller than SSIZE_MAX
Returns
On success, zero is returned. On error, -1 is returned and error message printed.

Referenced by coder_passthru().